Re: [PATCH net 1/2] net: ipa: only clear hardware state if setup has completed

From: Jakub Kicinski
Date: Fri Oct 09 2020 - 15:25:23 EST


On Tue, 6 Oct 2020 16:30:46 -0500 Alex Elder wrote:
> In the setup phase of initialization, GSI firmware gets loaded
> and initialized, and the AP command TX and default RX endpoints
> get set up. Until that happens, IPA commands must not be issued
> to the hardware.
>
> If the modem crashes, we stop endpoint channels and perform a
> number of other activities to clear modem-related IPA state,
> including zeroing filter and routing tables (using IPA commands).
> This is a bug if setup is not complete. We should also not be
> performing the other cleanup activity in that case either.
>
> Fix this by returning immediately when handling a modem crash if we
> haven't completed setup.
>
> Fixes: a646d6ec9098 ("soc: qcom: ipa: modem and microcontroller")
> Tested-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> Signed-off-by: Alex Elder <elder@xxxxxxxxxx>

> diff --git a/drivers/net/ipa/ipa_modem.c b/drivers/net/ipa/ipa_modem.c
> index e34fe2d77324e..dd5b89c5cb2d4 100644
> --- a/drivers/net/ipa/ipa_modem.c
> +++ b/drivers/net/ipa/ipa_modem.c
> @@ -285,6 +285,9 @@ static void ipa_modem_crashed(struct ipa *ipa)
> struct device *dev = &ipa->pdev->dev;
> int ret;
>
> + if (!ipa->setup_complete)
> + return;
> +
> ipa_endpoint_modem_pause_all(ipa, true);
>
> ipa_endpoint_modem_hol_block_clear_all(ipa);

The only call site already checks setup_complete, so this is not needed,
no?

$ git grep -C2 ipa_modem_crashed\(
drivers/net/ipa/ipa_modem.c-
drivers/net/ipa/ipa_modem.c-/* Treat a "clean" modem stop the same as a crash */
drivers/net/ipa/ipa_modem.c:static void ipa_modem_crashed(struct ipa *ipa)
drivers/net/ipa/ipa_modem.c-{
drivers/net/ipa/ipa_modem.c- struct device *dev = &ipa->pdev->dev;
--
drivers/net/ipa/ipa_modem.c- notify_data->crashed ? "crashed" : "stopping");
drivers/net/ipa/ipa_modem.c- if (ipa->setup_complete)
drivers/net/ipa/ipa_modem.c: ipa_modem_crashed(ipa);
drivers/net/ipa/ipa_modem.c- break;
drivers/net/ipa/ipa_modem.c-